Vitamin D and the Prevention of Multiple Sclerosis

Higher vitamin D levels in a person’s blood have been found to be associated with a lower incidence of multiple sclerosis symptoms and a slower progression of the disease, according to a new study recently reported at an annual international conference in Copenhagen. The study is only the latest to show what appear to be protective benefits by vitamin D against the onset of subsequent MS symptoms in patients clinically diagnosed with this disease.

Vitamin D is an important compound that’s required for many bodily processes; one of its primary functions is to help regulate intestinal absorption of the minerals calcium and phosphorus (phosphate), which are used by all of the body’s cells for basic cellular regulation, and which give bones and teeth their strength and structure.

Vitamin D is a key component in immune system response, and in the transmission of electrical messages between the brain and all the body’s parts.

It now appears that vitamin D also protects against neurodegenerative and neuroimmune disease, as in the case of MS. Researchers have in fact concluded that the benefits of vitamin D supplementation are equivalent to those of prescription immunosuppressants, without the severe side effects that these can sometimes cause. Experts on MS are now recommending to patients that they get adequate levels of vitamin D, both to control the illness and to help prevent complications such as falls and fractures.

A person who is diagnosed with MS should ask their health care provider for a vitamin D reading, which can be obtained through a blood test. The test to ask for is the 25-hydroxy vitamin D test, which is the most accurate measurement of vitamin D content in your system. Often, this initial reading will be low, in which case vitamin D supplementation may be in order, in consultation with your doctor.

Though there are some foods that have vitamin D or are enriched with the vitamin, these dietary sources may not be sufficient to supplement levels in a person who is D-deficient. Supplementation should be with vitamin D3, or cholecalciferol; that’s the most active form of vitamin D and is the kind made by the skin naturally when exposed to sunlight.

The Sun: A Natural Source of Vitamin D

Vitamin D is called the sunshine vitamin because the skin synthesizes it when it’s exposed to sunlight — specifically, when it’s exposed to UVB rays.

The Sun emits three types of ultraviolet (UV) rays: UVA, UVB and UVC. UVC wavelengths, the shortest, are absorbed largely by the ozone layer and don’t reach Earth’s surface in most places. UVA and UVB are the ones we all hear about, and from which we need to protect ourselves, since they do penetrate the atmosphere. Excessive exposure to either UVA or UVB rays, or both, has been linked to bad outcomes, including premature skin aging, eye disease such as cataracts, and different skin cancers (some of which are deadly).

Excessive exposure to UVA or UVB rays has also been found to suppress immune system function and weaken the body’s ability to fight off illnesses.

The Sun’s rays are powerful, and a person only needs a little bit of Sun, to synthesize more than enough vitamin D for the day. Health experts believe that as little as 15 minutes of Sun exposure a day — using no sunscreen and exposing plenty of skin — is sufficient to make enough vitamin D. You could also get a little more Sun — say, 30 minutes — every other day.

Researchers believe that a person’s Sun exposure should equal half of what it would take for that person’s skin to start turning pink. In other words, if you normally start to burn after 20 minutes of Sun, you should be in the Sun without protection for only 10 minutes. (Sunburn causes cumulative damage to the skin and is associated with skin cancer; therefore, it should be avoided.)

How much vitamin D your skin makes will depend on your location, the season, time of day, your skin’s natural color and your age.

People closer to the equator (such as those living in Florida) get more UVB radiation than those living farther from the equator. The farther north or south you go from the equator, the less UVB radiation you’ll get. Also, UVB rays are more abundant in the summer and spring; in most places throughout the world, people may need D supplementation to have optimal D levels in the wintertime, because of decreased solar radiation reaching Earth.

In the United States, the majority of UVB radiation hits us between 10 a.m. and 4 p.m., from April to October.

Melanin, the pigment that causes a person’s skin to be naturally dark, acts as a natural sunscreen. Therefore, fair-skinned people will only need minutes’ exposure to sunlight, whereas a dark-skinned person will require much longer exposure (up to 10 times as long) to synthesize the same amount of vitamin D.

Older folks will also synthesize less vitamin D from the Sun, as they have lower concentrations in their skin of a vitamin D precursor (7-DHC).

Other factors that will influence how much UVB your skin absorbs:

Clouds: a cloudy day will cause less UVB to reach your skin (though longer UVA wavelengths can still get through and you can still burn)

Being behind glass: glass blocks all UVB rays; thus, you cannot make vitamin D if you’re in the Sun, but behind glass

Air pollution: pollution particles absorb UVB rays or reflect them back into space; therefore, if you live in a city with a lot of pollution, your skin will make less vitamin D (as a partial solution to this, try getting your sunshine during hours that don’t coincide with rush-hour traffic and on weekends)

Sunscreen blocks nearly all UVB absorption; sunscreen with an SPF (Sun protection factor) of 8 reduces vitamin D production in the skin by more than 95 percent

That said, if you know you’ll be in the Sun much longer than 15 or 30 minutes, do apply a natural sunscreen to prevent skin damage, or don protective clothing like a wide-brimmed hat, UV-blocking sunglasses, and a long-sleeved shirt after a short unprotected exposure. Tightly-woven, loose-fitting clothes provide the best protection.

Exercise and MS:

As a final note, back in the 1970s, doctors used to tell MS patients to avoid exercise, as it was believed to be bad for the illness. But now, regular exercise is believed to improve fitness and function in people with mild MS, and maintain function in people with moderate to severe disability. Both aerobic exercise and resistance training are now thought to improve muscle function and strength, tolerance to exercise, and mobility in people with severe disability. That’s in addition to the well-known benefits of exercise to mood and overall health.

In his oral platform presentation at the annual meeting of the European Committee for Treatment and Research in Multiple Sclerosis, Ascherio

The ‘normal’ level of Vitamin D he was talking about in his study is what is needed to prevent rickets. It is not a very high level of Vitamin D. I think supplements rovements in the health status of our patients.”